In the related art, direct current (DC)-DC converters are used in electronic devices to convert direct current power voltages into necessary direct current voltages of circuits or components inside the electronic devices. As types of DC-DC converters, for example, a linear type converter in which variation is cut by a semiconductor element and a switching type converter in which a switching element is turned on or off can be exemplified. Of these types, a switching type is often used since conversion efficiency is high.
As control of the switching type, pulse frequency modulation (PFM) control in which a frequency is controlled and pulse width modulation (PWM) control in which a pulse width is controlled can be exemplified. In the PWM control, irrespective of the size of a load, a certain switching loss occurs due to switching being performed at a certain frequency. In contrast, in the PFM control, as a load is smaller, a switching frequency decreases. Therefore, it is possible to reduce the switching loss with a light load. Therefore, the PFM control is often used with a light load (for example, see Non-Patent Literature 1).